I honestly wonder about several customers per shift that I work. I've had my fair share of both BP and BPD behaviors/attitude issues, so my first thought when running into certain behaviors/attitudes in others is, "I wonder what you have?" I can't help it after my own journey and all of the people I've known who also went through mental illness/disorder journeys.

Had a customer two days ago who was in a very sarcastic rage over everything. I was just ringing up his items and didn't even say anything the whole time because I felt like he wanted to fight someone. At one point he was half-yelling that the music in the store was too loud and that it sucked, and then he started loudly pretend-singing along in a very mocking way. He just seemed severely agitated and couldn't stop talking. I couldn't help but find it more curious than anything else, wondering what his would-be diagnosis was.